Gas-cushion vehicles

ABSTRACT

A water reaction propulsion mechanism for the vehicle is housed within a skeg or keellike member located within the gas-cushion space of the vehicle and is retractable to prevent damage to the propulsion mechanism when the vehicle is temporarily on land or in very shallow water. Auxiliary propulsion means are provided for use when said member is retracted.

United States Patent [72] Inventor Rowland D. Hunt Fareharn. England[21] Appl. No 788.232

[22] Filed Dee.31,l968

I45) Patented July 6, i971 [73) Assignee Vesper Llmited [32] PriorityJan. II, 1968 [33] Great Britain [S4] GAS-CUSHION VEHICLES 10 Claims, 5Drawing Figs.

[52] U.S. Cl 114/67, l l4/l4l [5 I Int. Cl .t B63!) 1/38 [50] Field ofSearch 114/671, I41

[56] References Cited UNITED STATES PATENTS 93 L159 8/1909 Striblingll4/l4l 3,384,!98 5/1968 Jones et al. .4 l14/67 Primary Examiner-AndrewH. Farrell Attorney-Norris and Bateman ABSTRACT: A water reactionpropulsion mechanism for the vehicle is housed within a skeg 0t keellikemember located within the gascushion space of the vehicle and isretractable to prevent damage to the propulsion mechanism when thevehicle is temporarily on land or in very shallow water. Auxiliarypropulsion means are provided for use when said member is retracted.

PATENIEU JUL slan 3,590,764

INVBN'IOR ROWLAND DE LVI LLE HUNT PATENTEI] JUL 6 l9?! SHEET 2 UF 2INVENTOR ROWLAND mLvgLLE HUNT GAS-CUSHION VEHICLES BACKGROUND OFINVENTION The invention relates to gas-cushion vehicles, and more particularly to gas-cushion vehicles of the type provided with waterreaction propulsion mechanism such as pumps for producing water jets, orwater screws.

It has hitherto been envisaged that a gas-cushion vehicle of the typereferred to should operate from a pier or floating dock with sufficientdepth of water at low tide to keep the dock afloat and enable thevehicle to maneuver. This requirement calls for an expensive terminalstructure.

SUMMARY OF INVENTION The object of the invention is to eliminate theneed for such a vehicle to operate from a pier or floating dock.

According to the invention, a gas-cushion vehicle is provided with atleast one means housing water reaction propulsion mechanism, the wholeor a part of the or each means being a retractable member.

BRIEF DESCRIPTION OF DRAWINGS Four embodiments of the invention will nowdescribed by way of example only, with reference to the accompanyingdiagrammatic drawings of which:

FIG. 1 is a sectional side view of part of an air-cushion vehicleshowing a preferred embodiment of the invention;

FIG. 2 is a sectional view on the line 2-2 in FIG. I;

FIG. 3 is a sectional view on the line 3-3 in FIG. I;

FIG. 4 is a sectional side view of an air-cushion vehicle showinganother embodiment ofthe invention; and

FIG. 5 is a sectional end view of part of an air-cushion vehicle showinga further embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS In the preferred embodiment of theinvention, see FIGS. 1, 2, and 3 an aircushion vehicle has a hull 11carrying a full flexible skirt I2 and a power unit 13 driving at leastone fan for supplying air under pressure to the space enclosed by theskirt 12 to provide an air-cushion for supporting the vehicle. Waterreaction propulsion mechanism for the vehicle comprises two axial flowpumps 14 each driven, via shafts 41, 42 and 43 and bevel gear units 44and 45, by a power unit IS. The pumps 14 are housed within the lowerparts 17 of respective laterally spaced parallel skegs or keellikemembers I6, the upper parts of the skegs 16 being above the waterline I9when the vehicle is supported by its air-cushion. The lower part I7 ofeach skeg I6 is pivotable relative to the upper part thereof about alongitudinal hinge l8, coaxial with the shaft 43, by power operatedmeans (not shown). The inlet 20 of each pump 14 is formed in associatedlower part 17 and the outlet 46 thereof opens from said part into thecushion space. A flap 47 can be moved between an inoperative position(not shown) and an operative position shown in full lines in FIG. 1 toobstruct the normal outlet 46 of each pump 14 whereupon the water isexpelled through vanes 48 for reverse thrust. Two laterally spaced highpower/weight ratio gas-turbine jet engines or rocket motors 21 areprovided at the stern of the vehi cle as auxiliary propulsion means, andtwo laterally spaced docking supports 22 project from the underside ofthe hull I1 near its forward end.

When travelling over water, the vehicle is supported by the air-cushionand propelled by water ejected at high velocity from the pump outlets46. In order to turn the vehicle the pumps I4 are operated individuallyor at relatively different speeds, or the thrust of them is reversed bymeans of its flap 47. For reverse travel of the vehicle, both of theflaps 47 are moved into their operative positions. When it is desired tooperate temporarily in extremely shallow water or on land, the In driveto the pumps 14 is discontinued and the lower parts 1 of the skegs I6are swung upwardly by the power-operated 75 means. When proceedingdirectly on to a beach or the like, the momentum of the vehicle may belarge enough to carry it sufficiently clear of the water to enable anycargo to be unloaded or loaded without the need of specially constructeddocking facilities. Upon reaching a suitable position for transferringcargo the supply of air under pressure to the cushion space is cut offand the vehicle comes to rest on the supports 22 and the upper parts ofthe skegs I6. Return to the water may be possible by reinstating theair-cushion and allowing the vehicle simply to slide down the beach.When the vehicle has returned to relatively deep water the lower parts17 of the skegs 16 are swung back into operative position by thepoweroperated means and the vehicle is once again propelled by the pumps14. In extremely shallow water, and in difficult conditions on land, forexample where the slope of the beach is adverse or the vehicle hasinsufficient momentum, or possibly where there are very strong winds,the engines 2! are employed to propel the vehicle temporarily when thelower parts l7 of the skegs 16 are retracted and the pumps 14 areinoperative. The engines 21 are operated together to propel the vehicleforwards and individually or at relatively different speeds to turn thevehicle.

In another embodiment of the invention (see FIG. 4 in which partscorresponding to equivalent parts in FIGS. 1, 2 and 3 are identified bythe same numbers), the water reaction propulsion mechanism in each oftwo laterally spaced skegs 16 is a vertical stack of individual pumps 14which are connected in parallel, housed in the upper part of the skeg,and mounted on a common drive shaft projecting vertically downwards fromthe associated engine 15. The lower part I7 of the skeg 16 contains thepump inlet 20 and is pivotable about a longitudinal hinge I8.

In a further embodiment of the invention, see FIG. 5, the drive to astack of pumps 14 is via bevel gearing 23, 24 and the major part 25 of askeg contains said pumps and is pivotable about a longitudinal hingecoaxial with the driving gear 23.

lclaim:

1. A gas-cushion vehicle having a keellike member within its cushionspace which extends downwardly from its hull to a point below thewaterline and houses a pump assembly for producing a waterjet,characterized in that at least that part of said member which extendsbelow the waterline is retractable and contains the inlet of saidassembly.

2. A gas-cushion vehicle having a keellike member within its cushionspace which extends downwardly from its hull to a point below thewaterline and houses a water reaction propulsion mechanism,characterized in that at least that part of said member which extendsbelow the waterline is retractable by pivotal movement about an axisextends longitudinally of the vehicle.

3. A gas-cushion vehicle according to claim 2, 2 further characterizedin that only part of said keellike member is retractable and is hingedfor displacement relative to the remainder of said member about saidaxis.

4. A gas-cushion vehicle according to claim 2, 2 further characterizedin that auxiliary propulsion means other than of water reaction type areprovided.

5. A gas-cushion vehicle according to claim 4, 4 further characterizedin that said auxiliary propulsion means are of air reaction type.

6. A gas-cushion vehicle having a keellike member within its cushionspace which extends downwardly from its hull to a point below thewaterline and houses a pump assembly for producing a water jet,characterized in that part of said member which extends below thewaterline is retractable and contains the inlet of said assembly, theretractable part is hinged for displacement relative to the remainder ofsaid member about an axis which extends longitudinally of the vehicle,and auxiliary propulsion means other than of water reaction type areprovided.

7. A gas-cushion vessel adapted for water travel comprising a hullhaving a depending full flexible skirt and power driven means supplyingair under pressure within said skirt, laterally spaced keellike membersdepending from said hull within the skirt. each of said memberscomprising a lower portion hinged about a longitudinal axis, andlongitudinal water passages in each of said members containingindependently operable power driven pump means.

8. [n the vessel defined in claim 7, each of said pump means comprisinga pump having its axis substantially coincident with said hinge axis.

9. A gas-cushion vessel adapted for water travel comprising a hullhaving a depending full skirt and power driven means supplying air underpressure within said skirt, at least one keellike member depending fromsaid hull within the skirt. said member having a lower portion thatprojects below the waterline and is retractable about a longitudinalaxis, and propulsion means comprising a stack of power driven pumpsmounted in the upper portion of said member and disposed in waterpassage means extending mainly longitudinally through said member.

10. A gas-cushion vessel adapted for water travel comprising a hullhaving a depending full skirt and power driven means supplying air underpressure within said skirt, at least one keellike member depending fromsaid hull within the skirt, said member having a lower portion thatprojects below the waterline and is retractable about a longitudinalaxis, propulsion means comprising a stack of power driven pumps mountedin said lower portion of said member and disposed in water passage meansextending through said member, and drive means connecting saidpropulsion means to a source of power carried by said hull.

1. A gas-cushion vehicle having a keellike member within its cushion space which extends downwardly from its hull to a point below the waterline and houses a pump assembly for producing a water jet, characterized in that at least that part of said member which extends below the waterline is retractable and contains the inlet of said assembly.
 2. A gas-cushion vehicle having a keellike member within its cushion space which extends downwardly from its hull to a point below the waterline and houses a water reaction propulsion mechanism, characterized in that at least that part of said member which extends below the waterline is retractable by pivotal movement about an axis extends longitudinally of the vehicle.
 3. A gas-cushion vehicle according to claim 2, 2 further characterized in that only part of said keellike member is retractable and is hinged for displacement relative to the remainder of said member about said axis.
 4. A gas-cushion vehicle according to claim 2, 2 further characterized in that auxiliary propulsion means other than of water reaction type are provided.
 5. A gas-cushion vehicle according to claim 4, 4 further characterized in that said auxiliary propulsion means are of air reaction type.
 6. A gas-cushion vehicle having a keellike member within its cushion space which extends downwardly from its hull to a point below the waterline and houses a pump assembly for producing a water jet, characterized in that part of said member which extends below the waterline is retractable and contains the inlet of said assembly, the retractable part is hinged for displacement relative to the remainder of said member about an axis which extends longitudinally of the vehicle, and auxiliary propulsion means other than of water reaction type are provided.
 7. A gas-cushion vessel adapted for water travel comprising a hull having a depending full flexible skirt and power driven means supplying air under pressure within said skirt, laterally spaced keellike members depending from said hull within the skirt, each of said members comprising a lower portion hinged about a longitudinal axis, and longitudinal water passages in each of said members containing independently operable power driven pump means.
 8. In the vessel defined in claim 7, each of said pump means comprising a pump having its axis substantially coincident with said hinge axis.
 9. A gas-cushion vessel adapted for water travel comprising a hull having a depending full skirt and power driven means supplying air under pressure within said skirt, at least one keellike member depending from said hull within the skirt, said member having a lower portion that projects below the waterline and is retractable about a longitudinal axis, and propulsion means comprising a stack of power driven pumps mounted in the upper portion of said member and disposed in water passage means extending mainly longitudinally through said member.
 10. A gas-cushion vessel adapted for water travel comprising a hull having a depending full skirt and power driven means supplying air under pressure within said skirt, at least one keellike member depending from said hull within the skirt, said member having a lower portion that projects below the waterline and is retractable about a longitudinal axis, propulsion means comprising a stack of power driven pumps mounted in said lower portion of said member and disposed in water passage means extending through said member, and drive means connecting said propulsion means to a source of power carried by said hull. 